Re: PATCH: --with-sysroot for GDB

[Elena Zannoni <ezannoni at redhat dot com>]

Daniel Jacobowitz writes:
 > [Copied to Dan K. 'cause I know he'll like it :)]
 > 
 > Both binutils and GCC now support (although GCC's support isn't quite
 > finished yet, working on it...) a mechanism called "sysroot" for
 > handling cross environments.  The basic principal is that anything that
 > would normally access the "target" filesystem does so just as if it
 > were a native debugger running on $target, but prefixes all paths with
 > the value of the sysroot prefix.  We use $target/usr/include,
 > $target/etc/ld.so.conf, $target/lib, et cetera.  This is really great
 > for people using, for instance, gdbserver to debug a remote GNU/Linux
 > installation.  I bet the QNX people could use this, too.
 > 
 > Free bonus: as long as the sysroot is actually within $exec_prefix
 > (otherwise the relocation functions don't work right), it will move
 > along with the binary.  You can pick up the whole tree, drop it
 > somewhere else, and keep using it; no rebuild, no reconfigure.
 > 
 > Here's a patch to do the same thing in GDB.  Right now all it sets is
 > solib-absolute-prefix; that's because I can't think of anything else it
 > should affect, but if you have any ideas speak right up.
 > 
 > It also documents solib-absolute-prefix and solib-search-path, which
 > have been conspicuously missing from the manual for some time.
 > 
 > Thoughts?  I'll look to apply this in a couple of days if no one
 > objects to the way I implemented it.

main.c ok, except for.... see below:

 > 
 > -- 
 > Daniel Jacobowitz
 > MontaVista Software                         Debian GNU/Linux Developer
 > 
 > 2003-01-09  Daniel Jacobowitz  <drow@mvista.com>
 > 
 > 	* Makefile.in (TARGET_SYSTEM_ROOT, TARGET_SYSTEM_ROOT_DEFINE): New
 > 	variables.
 > 	(main.o): Custom rule which uses $(TARGET_SYSTEM_ROOT_DEFINE).
 > 	* configure.in: Add --with-sysroot.
 > 	* main.c (gdb_sysroot): New variable.
 > 	(captured_main): Initialize gdb_sysroot.
 > 	* defs.h (gdb_sysroot): New extern declaration.
 > 
 > 2003-01-09  Daniel Jacobowitz  <drow@mvista.com>
 > 
 > 	* gdb.texinfo (Files): Document solib-absolute-prefix and
 > 	solib-search-path.
 > 
 > Index: Makefile.in
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/Makefile.in,v
 > retrieving revision 1.310
 > diff -u -p -r1.310 Makefile.in
 > --- Makefile.in	6 Jan 2003 20:45:30 -0000	1.310
 > +++ Makefile.in	9 Jan 2003 17:29:16 -0000
 > @@ -136,6 +136,10 @@ INTL_CFLAGS = -I$(INTL_DIR) -I$(INTL_SRC
 >  # Where is the ICONV library?  This can be empty if libc has iconv.
 >  LIBICONV = @LIBICONV@
 >  
 > +# Did the user give us a --with-sysroot option?
 > +TARGET_SYSTEM_ROOT = @TARGET_SYSTEM_ROOT@
 > +TARGET_SYSTEM_ROOT_DEFINE = @TARGET_SYSTEM_ROOT_DEFINE@
 > +
 >  #
 >  # CLI sub directory definitons
 >  #
 > @@ -1402,6 +1406,11 @@ hpux-thread.o: $(srcdir)/hpux-thread.c
 >  	$(CC) -c $(INTERNAL_CFLAGS) -I$(srcdir)/osf-share \
 >  		-I$(srcdir)/osf-share/HP800 -I/usr/include/dce \
 >  		$(srcdir)/hpux-thread.c
 > +
 > +# main.o needs an explicit build rule to get TARGET_SYSTEM_ROOT and BINDIR.
 > +main.o: main.c
 > +	$(CC) -c $(INTERNAL_CFLAGS) $(TARGET_SYSTEM_ROOT_DEFINE) \
 > +		-DBINDIR=\"$(bindir)\" $(srcdir)/main.c
 >  
 >  # FIXME: Procfs.o gets -Wformat errors because things like pid_t don't
 >  # match output format strings.
 > Index: configure.in
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/configure.in,v
 > retrieving revision 1.116
 > diff -u -p -r1.116 configure.in
 > --- configure.in	4 Jan 2003 23:47:12 -0000	1.116
 > +++ configure.in	9 Jan 2003 17:29:18 -0000
 > @@ -851,6 +851,38 @@ fi
 >  
 >  dnl Handle optional features that can be enabled.
 >  
 > +AC_ARG_WITH(sysroot,
 > +[  --with-sysroot[=DIR] Search for usr/lib et al within DIR.],
 > +[
 > + case ${with_sysroot} in
 > + yes) AC_ERROR(with-sysroot must specify path) ;;
 > + *) TARGET_SYSTEM_ROOT=$with_sysroot ;;
 > + esac
 > +
 > + TARGET_SYSTEM_ROOT_DEFINE='-DTARGET_SYSTEM_ROOT=\"$(TARGET_SYSTEM_ROOT)\"'
 > +
 > + if test "x$exec_prefix" = xNONE; then
 > +  if test "x$prefix" = xNONE; then
 > +   test_prefix=/usr/local
 > +  else
 > +   test_prefix=$prefix
 > +  fi
 > + else
 > +  test_prefix=$exec_prefix
 > + fi
 > + case ${TARGET_SYSTEM_ROOT} in
 > + ${test_prefix}*)
 > +   t="$TARGET_SYSTEM_ROOT_DEFINE -DTARGET_SYSTEM_ROOT_RELOCATABLE"
 > +   TARGET_SYSTEM_ROOT_DEFINE="$t"
 > +   ;;
 > + esac
 > +], [
 > + TARGET_SYSTEM_ROOT=
 > + TARGET_SYSTEM_ROOT_DEFINE='-DTARGET_SYSTEM_ROOT=\"\"'
 > +])
 > +AC_SUBST(TARGET_SYSTEM_ROOT)
 > +AC_SUBST(TARGET_SYSTEM_ROOT_DEFINE)
 > +
 >  # NOTE: Don't add -Wall or -Wunused, they both include
 >  # -Wunused-parameter which reports bogus warnings.
 >  # NOTE: If you add to this list, remember to update
 > Index: defs.h
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/defs.h,v
 > retrieving revision 1.107
 > diff -u -p -r1.107 defs.h
 > --- defs.h	6 Jan 2003 18:49:08 -0000	1.107
 > +++ defs.h	9 Jan 2003 17:29:18 -0000
 > @@ -169,6 +169,9 @@ extern int xdb_commands;
 >  /* enable dbx commands if set */
 >  extern int dbx_commands;
 >  
 > +/* System root path, used to find libraries etc.  */
 > +extern char *gdb_sysroot;
 > +
 >  extern int quit_flag;
 >  extern int immediate_quit;
 >  extern int sevenbit_strings;
 > Index: main.c
 > ===================================================================
 > RCS file: /cvs/src/src/gdb/main.c,v
 > retrieving revision 1.20
 > diff -u -p -r1.20 main.c
 > --- main.c	26 Sep 2002 17:46:04 -0000	1.20
 > +++ main.c	9 Jan 2003 17:29:18 -0000
 > @@ -65,6 +65,9 @@ int xdb_commands = 0;
 >  /* Whether dbx commands will be handled */
 >  int dbx_commands = 0;
 >  
 > +/* System root path, used to find libraries etc.  */
 > +char *gdb_sysroot = 0;
 > +
 >  struct ui_file *gdb_stdout;
 >  struct ui_file *gdb_stderr;
 >  struct ui_file *gdb_stdlog;
 > @@ -200,6 +203,29 @@ captured_main (void *data)
 >  
 >    /* initialize error() */
 >    error_init ();
 > +
 > +  /* Set the sysroot path.  */
 > +#ifdef TARGET_SYSTEM_ROOT_RELOCATABLE
 > +  gdb_sysroot = make_relative_prefix (argv[0], BINDIR, TARGET_SYSTEM_ROOT);
 > +  if (gdb_sysroot)
 > +    {
 > +      struct stat s;
 > +      int res = stat (gdb_sysroot, &s) == 0 && S_ISDIR (s.st_mode);

please split this statement into an if + assignment.